External cardiac massage training device



Oct. 5, 1965 H. M. JAMES 3,209,469

EXTERNAL CARDIAC MASSAGE TRAINING DEVICE Filed March 7, 1962 2Sheets-Sheet 1 FIG-4 79 7s 78 78 80 T v 37 82 1 b m1. m. a 6] L-I 2-;'Imh- "Hlln l I I Q I m nim? H} e 25 -52 H] m lllli "[ln up A? mINVENTOR. Lg an 9 38 HAROLD M. JAMES, MD. 85 33 ATTORNEYS Oct. 5, 1965JAMES 3,209,469

EXTERNAL CARDIAC MASSAGE TRAINING DEVICE Filed March 7, 1962 2Sheets-Sheet 2 FIG-5 FIG-6 8 5O 58 N 5! 7s MZS B7 54 54$: I 55 78 55 5s\5s 05g 140 W48 1 46 ,,f 35 36 g 80 L. e0 62 83 36 67 82 I0 82 45 46 a L58 as F lG-T I 58% 79 /"Win 0", lyglllllllilllmlfl INVENTOR. HAROLD M.JAMES M.D.

ATTORNEYS United States Patent Office 3,209,469 Patented Oct. 5, 19653,209,469 EXTERNAL CARDIAC MASSAGE TRAINING DEVICE Harold M. James, 516Shafor Blvd., Dayton 19, Ohio Filed Mar. 7, 1962, Ser. No. 178,185 7Claims. (Cl. 35-17) This invention relates to a training deviceparticularly adapted for training persons to execute properly externalcardiac massage upon victims of cardiac arrest.

It has been known for some time that victims of cardiac arrest,attributable to any number of causes, can often be helped by cardiacmassage to such an extent that the heart is caused to begin beatingagain by itself. The most popular system up to this time has been toopen the chest through surgery and to reach into the chest cavity andpalpitate and massage the heart with the fingers. Obviously, this systemis only to be employed where all other means of reviving the patient, orreviving the heart beat, have been unsuccessful, since the quick surgeryrequired is dangerous, and may be particularly so if the patient is innon-sterile surroundings. As a result of these difiiculties a system hasbeen developed which is known as external cardiac massage.

The external massage system operates because of certain physicalconstruction of the human body. With a person, in the present case thecardiac arrest victim, placed in the supine position, i.e., lying uponhis back, the heart is limited posteriorly by the vertebral column andanteriorly by the sternum or breast bone, the bone at which the ribsjoin along the front of the chest. The pericardium or sac whichsurrounds the heart restricts lateral motion of the heart. Therefore,with the victim in the supine position, when pressure is applied on thesternum the heart is pushed against the spine, forcing blood into thearteries as the pericardium is distorted outwardly by such downwardpressure. Relaxation of this presure allows the heart to fill withvenous blood. Because the thoracic cage in unconscious cardiac arrestvictims is flexible, the sternum can be depressed by a distance of oneand one-half to two inches (about three to five centimeters) withoutendangering the ribs.

Accordingly, the external cardiac massage system requires that thevictirn be placed in the supine position, and force applied against hissternum, in a regular or rhythmic fashion, and thus to force blood intothe arteries and maintain an artificial circulation of the bloodparticularly to the lungs and to the brain. This action, coupled withventilation of the respiratory system, as by mouth-tomouth ormouth-to-nose artificial respiration, will maintain adequate flow ofblood and thus an adequate supply of oxygen to the brain. It has beendetermined that if a victim of cardiac arrest is allowed to remainwithout restoration of heart beat, either self-sustained or by suchmassage, permanent damage to the brain will result within approximatelyfour minutes.

Accordingly, the external cardiac massage system assures that thefunction of the heart in circulating or pumping blood from the venoussystem into the arteries is maintained, and this action coupled withartificial respiration will maintain the required supply of oxygen containing blood to the brain to circumvent such permanent brain damage.

The external cardiac massage system is of course much more acceptablethan the open chest massage system heretofore known. Obviously, it is nolonger necessary always to make an incision in the chest, and the dangerof infection is essentially eliminated. Moreover, laymen can be readilytrained in the technique, and thus lives can be saved in instances whereno medically trained person is at hand.

In performing the external massage, the person doing the massage placesthe heel of one hand, in some cases with the heel of the other hand ontop of it, on the lower sternum, approximately one third of the wayupward from the xiphoid, which is at the lower end of the sternum orbreast bone, and firm pressure is applied vertically through the heel ofthe lowermost hand about once per second. At the end of each pressurestroke, the hands are completely relaxed to permit full chest expansion.The massaging person positions his body, particularly his upper torsoand shoulders, such that the body weight can assist in applyingpressure. Proper technique will result in forcing the sternum one andone-half to two inches (or three to five centimeters) toward the spine.If two persons are available, another can maintain mouth-to-mouth ormouth-to-nose artificial respiration or ventilation while the firstperson proceeds with the cardiac massage. Respiration is efi'ected aboutonce every three to four seconds, and if only one person is available itis possible for him to interrupt the cardiac massage every twelve tofifteen seconds so to achieve three to five breaths of artificialrespiration and thus ventilate the lungs to assure that oxygen issupplied to the lungs and to the blood being circulated by the cardiacmassage.

The external massage system, once learned, can be used by properlytrained persons who do not have a general medical background. Forexample, members of rescue squads, fire departments or policedepartments, or the like, can be trained to perform the external cardiacmassage effectively. However, in such training 'it is necessary that thetrainee be permitted to practice the technique, and to learn properplacement of the hands. For example, if the fingers, particularly of thelower hand contacting the sternum, are'permitted to press against theribs of the victim, the force of the massage is exerted partially ontothe ribs, and it is quite possible that one or more ribs may befractured. Furthermore, the same pressure obviously is not required forchildren as for adults, nor for infants as for children. Therefore, thetrainee must learn to analyze the victim and his physical makeup, and toapply the proper pressure accordingly. As an example, the massage can beeffected on children using one hand only, with the heel of the handplaced on the sternum. On infants, it is necessary only to use the firsttwo fingers of one hand to press upon the sternum, and the rate at whichpressure is applied is generally increased for children and infants suchfor example that approximately ninety strokes per minute may be used fora child and in the neighborhood of one hundred twenty strokes per minute(in other words two per second instead of one) for infants.

If the trainee were to practice on humans simulating cardiac arrestvictims, it would of course be undesirable to practice on children orinfants. Even when practicing on adults, the force exerted on thesternum is considerable. When the person being massaged is notunconscious, the thoracic cage is not as flexible as with an actualunconscious victim, and the person simulating the victim would thus besubjected to considerable uncomfortable and in fact painful treatment.Realizing that this would be a time of training, it is quite possiblethat the trainee, not having mastered the technique but merely learningit, could likely injure the person simulating the victim, perhapsseriously if one or more ribs were broken and caused internal puncturewounds of one type or another.

Accordingly, the present invention provides a device which iseifectively used to train persons in the proper technique of applyingexternal cardiac massage to victims of cardiac arrest.

Another object of the invention is to provide such a device including apart simulating the sternum, wherein such part can be deflected byapplication of pressure by the trainee, and wherein proper and excessivedeflections of the plate, corresponding to proper and excessivedepressions of the sternum, will be indicated to the trainee thus tofamiliarize him with the feel of properly applied massage pressure.

Another object of the invention is to provide such a training deviceincluding a means for warning the trainee that his fingers areimproperly placed and could result in injury to a real victim.

Another object of the invention is to provide such a device wherein theresistance to motion of the sternum simulating plate can be changed togive the trainee the feel of different resistances as would beencountered in massaging children or infants.

Another object of the invention is to provide a training device whichwith its distinctive signals indicating adequate sternal pressure, therhythm of the trainee practicing the massage technique, excessivesternal pressure, excessive finger pressure against the ribs or theadjacent chest wall, with or without the combined pulmonaryresuscitation feature, provides a device which can be duplicated andconnected in parallel to a monitor panel or the like permitting trainingof several persons at one time with a trainer-observer being able toview such a monitor panel and accurately control the training of theseveral persons practicing on the individual units.

Other objects and advantages of this invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

In the drawings FIG. 1 is a perspective view of a training deviceaccording to the invention;

FIG. 2 is a view similar to FIG. 1, on a slightly larger scale, with thecover on the chest of the mannequin removed;

FIG. 3 is a side view on a larger scale of the device as shown in FIG.1;

FIG. 4 is a plan View on an enlarged scale showing only the details ofthe device simulating the sternum and the apparatus associatedtherewith;

FIG. 5 is an end view of the apparatus shown in FIG. 4, with the batteryand its mounting omitted;

FIG. 6 is a side view of the apparatus shown in FIG. 4, showing also indotted lines moved positions of the sternurn simulating device;

FIG. 7 is a schematic electrical diagram; and

FIG. 8 is a sectional view taken on line 8-8 of FIG. 6, and including anillustration of the hands of a trainee properly placed upon the devicein preparation for execution of the massage technique as it would beapplied to an adult.

Referring to the drawings, which illustrate a preferred embodiment ofthe invention, and particularly with reference to FIGS. 1, 2 and 3, thedevice includes a base 10 which is provided with suitable supportingrails or feet 12 adapted to rest upon the floor or upon a similarsurface. A mannequin 15 of the human chest, including the shoulders,neck, and the area of the upper abdominal cavity adjacent the bottom ofthe thoracic cage, is mounted upon the base 10 in a rigid position, forexample being fastened thereto by a number of clips 16. The mannequin ishollow, and the central chest area is provided with a removable cover18, held in place by a pair of pivoting clips 19, and centrally locatedon the mannequin. Preferably there is some indicia on the .cover,indicated generally by the reference numeral 20, to indicate the generallocation of the heart within the chest. For example, in one form of thedevice this area is painted red within the outline in FIG. 1. A handle21 preferably is fixed to the cover 18 to facilitate its movement, sincethe cover ordinarily is removed during use of the device.

The center of the cover is provided with an elongated aperture 23 whichextends centrally and longitudinally of the cover, as best seen in FIG.1, and a plate 25 or the like of the same general configuration as theopening 23, is mounted within the opening 23 and provides a meanssimulating the sternum or breast bone of the victim. Preferably, thisplate is provided with a locating notch or flat 26 at its upper edge tosimulate the location of the upper or sternal notch, at the top of thebreast bone, and at its lower end there is a similar notch 27 located tosimulate the xiphoid, the lower terminus of the sternum. The trainee canfeel these notches and thereby become acquainted with the manner inwhich he can locate the sternum on a cardiac arrest victim.

As mentioned in the introduction to this specification, the externalcardiac massage is generally accompanied by artificial respiration orventilation of the lungs, and the device may include provision fortraining in this respect also. For example, it may be desirable to traintwo persons as a team, one giving the cardiac massage and the othergiving mouth-to-mouth artificial respiration through the use of aconventional appliance 30 which fits within the mouth of the victim, andincludes a known tongue depressor (not shown) which assures a clearopening through the tubular body into the throat of the victim.Accordingly, the mannequin may be provided with a head 32 to which suchan appliance can be attached, and a suitable support 33 for the head isshown in FIG. 3. It should be understood, however, that the primarypurpose of the present device is to train persons to execute properlythe external cardiac massage, and that the head and appurtenant partsare not a necessary feature of the invention.

Within the mannequin 15, and mounted upon the base 10, there is asupporting frame provided by upper and lower mounting blocks or the likeindicated respectively at 35 and 36. The corners of these blocks arejoined by side rails 37 and 38, and the sternum simulating device orplate is formed by a relatively thick body 40 having a number oftransverse passages 41 (FIG. 8) through which resilient supportingmembers such as springs 42 extend, being anchore'l at their oppositeends to the rails 37 and 38. Beneath the block 40 there is a largerspring 45 (or its equivalent) which is engaged over suitable guides orshort posts 46, FIG. 6, and which provides a permanent predeterminedresistance to depression of the block 40, in conjunction with thesupporting spring members 42. It should be noted, particularly withreference to FIGS. 4 and 6, that one of the support springs, designated42a, is fastened at one end to the upper mounting end member 35, and atits other end to the block 40, and thus provides a restraining andlocating force directed transversely to the other springs 42.

Adjacent the lower end of the block 40, referring in this sense to FIG.2 and using the term lower as it would apply to the lower regions of thechest, there are a pair of guiding members in the form of angles 48which extend vertically alongside the block, in slightly spaced relationthereto, limiting the motion of the block in this area particularly toessentially up and down or vertical motion, indicated by the arrow inFIG. 8.

The actual sternum simulating plate is preferably constructed on theblock 40, and includes a main plate member 50 which is secured to theupper surface of block 40, and has a raised portion 51 which is a rigidpart of the plate 50. The portion 51 is located generally over the lowerthird and upward across the center of the plate 50. Plate members 52 and54 are secured to the plate member 50 through resilient members 55, suchas small blocks of rubber or the like, which normally hold the platemembers 52 and 54 slightly above the main plate member 50 and with theirupper surfaces coextensive with the surface of the central member 51.Between the main plate 50 and each of the plate members 52 and 54 thereare electrical contact members 58 normally main tained spaced apart bythe action of the resilient blocks 55. If the trainee places his handupon either of the plate members 52 or 54, this will tend to close thecontacts 58 providing a signal indicating that the trainee has notplaced his hand properly upon the sternum simulating device.

It has been established that because the thoracic cage in unconsciouspersons is flexible, the sternum can be depressed one and one-half totwo inches without endangering the ribs. It is therefore desirable totrain those who are learning the technique of external cardiac massagein the feel of the depression of the chest, particularly the sternum,this amount. Accordingly, the force required to depress the spring 45 ispredetermined, and in addition the further spring 60 is mounted betweena support bracket 62 and the lower end of the main plate member 50,particularly beneath the plate member 54. This spring 60 is removable,and different springs having different known rates may be substituted inthis position. Therefore, it is possible to provide differentpredetermined resistances to depression of the sternum simulatingdevice. In some instances, for example when it is desired to simulatethe relatively slight resistance which would be offered by the cheststructure of an infant, no spring at all may be required in thisposition, with the spring 45 being suflicient for the desired purpose.

In order to give the trainee a feeling for the proper rhythmicapplication of the desired force, the present invention provides asignaling system whereby the trainee is informed when he is depressingthe sternum simulating member a sufiicient amount, and a further signalis also provided to indicate when excessive force is being applied, suchas would endanger the chest structure of an actual patient. For thispurpose, a pair of contacts 65 and 66 are fastened to the lower side ofthe block 40. Beneath the contact 65 there is a contact preferably inthe form of the spring 67, spaced below the normal elevated position ofthe contact 65 by a distance of about three centimeters. Motion of thesternum simulating block construction to bring the contact 65 intoengagement with the spring contact 67 will represent the minimum desireddepression of the sternum in an actual patient.

Beneath the contact 66 there is a spring contact 68, spaced below thenormal elevated position of the contact 66 by a distance of about fivecentimeters. This distance represents the maximum desired depression ofthe sternum in a patient, beyond which the force exerted may bedangerous to the rib structure, in particular.

Both the contact members 65, 67 and 66, 68 are connected to actuateseparate and distinctive signals or indicators, visible (or audible) tothe trainee so that he will know when he is depressing the sternumsimulating device the proper amount, and not an excessive amount.Details of these signaling or indicating devices are describedhereinafter.

Referring particularly to FIG. 8, the correct position of the hands isillustrated upon the main upper plate member 51. The heel of one hand,shown here as left hand, is placed upon the sternum, and the fingers ofthat hand are maintained in an elevated position. The hand placementshown is that desired for massage of an adult, and thus the other orright hand is placed with its heel over the back of the left hand, andforce is exerted upon the sternum (in the patient) with both hands. Inmassaging a child, it would be desirable to use only one hand, in .theposition shown for the lower hand in FIG. 8. 'In applying massage to aninfant, only the first two fingers of one hand would be placed upon theplate 51.

Particularly when applying .the massage to adults or children, it isnecessary to develop the proper technique whereby the force is directedonto the sternum, and is not applied to adjacent areas of the rib cage.Thus, as previously mentioned, the fingers of the lowermost hand must bemaintained in an elevated position with respect to the chest. Forpurposes of illustration, a portion of the mannequin 15 is shown in FIG.8 in the area surrounding the sternum simulating device, and at anelevation which defines the exterior of the chest structure as it wouldappear in an actual victim. The dot-dash line 70 represents theextension of the chest (or the cover '18) toward the sternum simulatingdevice, but in actual use of the preferred form of the apparatus, thisarea is left open, the cover being removed.

A warning apparatus is provided to indicate incorrect placement of thefingers while practicing the message technique on the trainingapparatus. This apparatus is in the form of spaced contact springs and76, which are mounted on a frame 78, electrically insulated from oneanother. These springs form contacts at the elevation corresponding tothe chest surface (i.e., the location of spring 76) and if the fingersare lowered by the trainee to the point where the upper spring 75 iscarried into contact with the lower spring 76 during depression of thesternum simulating device, a circuit will be closed to actuate a furthersignal or indicating device. Thus, the trainee learns to maintain hisfingers properly away from the chest surface, to avoid closing thesecont-acts.

Preferably an adjustment is provided in the framework mounting thecontact springs 75 and 76. This may be in the form of suitable bolt andwing-nut fasteners 79 which mount the framework 78 on mounting angles80. Thus the proper elevation of the spring contacts 75 and 76,particularly the latter, can be attained. Furthermore, the base leg ofthe mounting angles 80 is received under a socket forming plate 82, atone side of the sternum simulating device, and an identical socketforming plate 83 (FIG. 4) is provided at the other side. Thus, theentire spring contact arrangement, including the mountings therefor, canbe placed on either side of the sternum simulating device in order toprovide the desired signaling or indicating function on either side ofthe sternum ac cording to the manner in which the trainee operates. Somepersons will prefer to kneel to the right side of the victim Whileothers will prefer to kneel on the left side, and it makes no differencewhich position is attained, so long as the hands are properly placed andused upon the sternum. Thus, the signaling contacts 75 and 76 can bemoved to the opposite side of the device from that shown in thedrawings, for training in either position.

FIG. 7 is a schematic diagram of a suitable electrical circuit for thesignaling devices. Pre-ferably these devices are in the form ofdifferently colored lights, as will be described, and these lights areactuated or energized by the various switch contacts previouslydescribed, according to the necessary signal. In order to providemaximum portability, the preferred embodiment employs a simple batterycircuit, using for example a conventional lantern battery 85, mounted onthe base of the apparatus and shown schematically in FIG. 7. Obviously,any other suitable source of electrical power can be utilized. As shownin FIG. 7, the contact-s 65 and 67 control the energization of a signallamp or bulb 90. when the trainee is executing the massage technique onthe training device, this lamp will light once for each downward orpressure stroke of the massage. The lighting of this lamp on each strokealso provides a guide to the trainee as he counts to learn propertiming, it being desirable to depress the sternum once each second,approximately, as previously explained. -In a preferred form of theapparatus the lamp is a White signal light. The contacts 66 and 68control energization of a warning lamp 92, preferably a red or otherwisevivid signal. When the trainee is depressing the sternum simulatingdevice an excessive amount, this signal will operate to provide thewarning to him that he is executing the massage too vigorously or withtoo great a downward force such as would be dangerous to a patient.

The contacts 75 and 76 are connected in circuit with the warning lamp94. This lamp also should be some rather vivid color, for example anorange or a different shade of red, preferably distinct from the lamp 92but still of a warning nature. Thus when the fingers of the traineeshands are placed too low or too close to the chest, this signal willlight. The contacts 58 are connected in parallel and either willenergize a further \warning lamp 96. This lamp or bulb, when lit,indicates to the trainee that he has not placed his hand properly on thesternum simulating device, either contacting the lower plate member 54or the upper plate member 2, and thus not having the correct placementof his hand to apply the force of the massage in the proper area of thesternum on an actual victim.

Obviously, other equivalent signaling or indicating devices, eithervisual or audible or both, can be employed within the scope of theinvention. However, the arrangements shown have proven completelysatisfactory in actual use, and are thus illustrated as being apreferred embodiment of the invention. It should also be understood thatthe particular construction of the sternum simulating means is, while inmany cases preferred, not essential to the invention. Many equivalentconstructions will suggest themselves to those skilled in the art. Theconstructions illustrated and described herein are however of a typewhich have actually proven satisfactory.

The location of the various signal lamps is discretionary, and hence hasnot been illustrated in any detail beyond the circuit diagram. If thedevice is provided as a single portable unit the various indicatingdevices, such as the lamps or bulbs, can be mounted on the mannequinwhere they are readily visible to the trainee and to the trainer who isinstructing. It is also within the perview of the invention to providemultiple training devices having connections to such indicating lamps ona remote monitor panel or board, with a set of indicator lamps for eachtraining device. With such an arrangement the trainer can observe andinstruct several trainees at the same time.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise form of apparatus and that changes may bemade therein without departing from the scope of the invention which isdefined in the appended claims.

What is claimed is:

1. A device for training persons to execute properly external cardiacmassage on victims of cardiac arrest, comprising a base, a mannequin ofthe human chest mounted on said base in simulated supine position,movable means positioned on said mannequin corresponding to the locationof the sternum, and forming a visible indication of such location on thechest, means mounting said movable means for motion in said mannequinsimulating the depression of the sternum required for cardiac massage,and means resisting depression of said movable means with a forcepredetermined to approximate the resistance to flexing of a humanthoracic cage.

2. A device for training persons to execute properly external cardiacmassage on victims of cardiac arrest, comprising a base, a mannequin ofthe human chest mounted on said base in simulated supine position,movable means positioned on said manequin corresponding to the locationof the sternum, said movable means including a main portioncorresponding to the correct placement of the hand of a trainee, firstand second members movably mounted on said main portion corresponding toincorrect placement of the hand, first and second sets of switchcontacts mounted on said first and second members and adapted to beactuated upon incorrect placement of the hand on said movable means,signal means operatively associated with said first and second sets ofcontacts for indicating the incorrect placement of the hand in responseto actuation of either of said contacts, means mounting said movablemeans for motion in said mannequin simulating the depression of thesternum required for cardiac massage, means resisting depression of saidmovable means with a force predetermined to approximate the resistanceto flexing of a human thoracic cage, and means operatively connected tosaid movable means indicating the acceptable limits of movements of thesternum attendant to proper cardiac massage.

3. Apparatus for instructing and training persons in the application ofexternal cardiac massage, comprising a plate constructed to simulate thesternum and forming a visible indication of the position of the sternumwith respect to the chest structure, means mounting said plate providingfor restrained movement thereof by the hand of a trainee in a mannercorresponding to depression of the human sternum with the body in supineposition, means resisting such motion of said plate with a predeterminedforce corresponding to resistance encountered in depressing the sternum,and signal means connected to indicate proper depression of said plateby the trainee.

4. Apparatus for instructing and training persons in the application ofexternal cardiac massage, comprising a device constructed to simulatethe sternum and forming a visible indication of the position of thesternum with respect to the chest structure, means mounting said deviceproviding for restrained motion thereof in a manner corresponding todepression of the human sternum with the body in supine position, meansresisting such motion of said device with a predetermined forcecorresponding to resistance encountered in depressing the sternum, afirst signal device connected to indicate motion of said devicecorresponding to sufficient depression of the sternum for effectiveheart massage, and a second signal device connected to indicate motionof said device corresponding to excessive depression of the sternumwhich could result in damage to the thoracic cage or organs containedtherein.

5. Apparatus for instructing and training persons in the application ofexternal cardiac massage, comprising a mannequin of the human chestincluding a device constructed to simulate the sternum, means mountingsaid sternum simulating device providing for restrained motion thereofin a manner corresponding to depression of the human sternum with thebody in supine position, means resisting such depression of said sternumsimulating device with a force predetermined in amount to the resistanceencountered due to limiting flexibility of the thoracic cage, and signalmeans operatively associated with said sternum simulating device forindicating application of force at an improper location on the sternum.

6. Apparatus for instructing and training persons in the application ofexternal cardiac massage, comprising a mannequin of the human chestincluding a device constructed to simulate the sternum, means mountingsaid sternum simulating device providing for restrained motion thereofin a manner corresponding to depression of the human sternum with thebody in supine position, means resisting such depression of said sternumsimulating device with a force predetermined in amount to the resistanceencountered due to limited flexibility of the thoracic cage, and signalmeans including a switch contact operatively mounted on said mannequinalongside said sternum simulating device and at essentially the level ofthe chest for teaching the trainee to hold his fingers in properlyelevated position above the ribs while exerting a suflicient depressingforce with the heel of his hand on said sternum simulating device.

7. A device for training persons to execute properly external cardiacmassage on victims of cardiac arrest, comprising a base, a mannequin ofthe human chest mounted on said base in simulated supine position,movable means positioned in said mannequin in a location correspondingto the sternum, mountings for said movable means confining movementthereof in said mannequin to motion simulating the depression andraising of the sternum required for external cardiac massage, adjustablemeans resisting depression of said movable means with a forcepredetermined to approximate the resistance to 9 It) flexing ofdifferent human thoracic cage structures, elec- FOREIGN PATENTS tricalcontacts arranged for selective operation by said 791741 3/58 GreatBritain movable means for indicating the limits of movement of saidmovable means corresponding to sufficient but not OTHER REFERENCESexcessive motion of the sternum required for efiective 5 Ald R h Labtori Inc., Catalog 31 cardiac massage. (1960).

Referelmes Cited y the Examine! EUGENE R. CAPOZIO, Primary Examiner.

UNITED STATES PATENTS ABRAHAM BERLIN, JEROME SCHNALL,

3,049,811 8/62 Ruben 35 17 LEONARD W. VARNER, Examiners.

1. A DEVICE FOR TRAINING PERSONS TO EXECUTE PROPERLY EXTERNAL CARDIACMESSAGE ON VICTIMS OF CARDIAC ARREST, COMPRISING A BASE, A MANNEQUIN OFTHE HUMAN CHEST MOUNTED ON SAID BASE IN SIMULATED SUPINE POSITION,MOVABLE MEANS POSITIONED ON SAID MANNEQUIN CORRESPONDING TO THE LOCATIONOF THE STERNUM, AND FORMING A VISIBLE INDICATION OF SUCH LOCATION ON THECHEST, MEANS MOUNTED SAID MOVABLE MEANS FOR MOTION IN SAID MANNEQUINSIMULATING THE DEPRESSION OF THE STERNUM REQUIRED FOR CARDIAC MESSAGE,AND MEANS RESISTING DEPRESSION OF SAID MOVABLE MEANS WITH A FORCEPREDETERMINED TO APPROXIMATE THE RESISTANCE TO FLEXING OF A HUMANTHORACIC CAGE.